1. Field of the Invention
The present invention relates in general to transport or handling carts, and more particularly to the handlebars for controlling and manoeuvering carts of this character, of the type wherein each upright comprises a metal wire or tube bent on itself at its upper end, the grip handle consisting of a transverse tube secured at either end to the top ends or elbows of said upright.
Control handlebars of this type are provided more particularly on transport carts put at the disposal of customers in selfservice shops and the like, such as supermarkets, and also in workshops. However, many other kinds of transport or handling carts are also provided with control handlebars of the same type.
2. Description of the Prior Art
At present, the ends of the transverse tube acting as a grip handle are secured in general to the upper ends of the uprightforming bent metal wire or tube by means of assembling devices comprising screw-or bolt-type clamping or locking means. Thus, the French Patent Application No. 70 24007 published under the No. 2,109,046 to the Applicant is directed to an assembling device intended for this purpose and consisting essentially of a pair of shells adapted to enclose between them the relevant upper portion of one of the cart handlebar uprights, one of these shells being formed with an integral stud adapted to engage the registering end of the grip-handle forming tube. These two members are subsequently tightly assembled by means of a screw or bolt engaging with its end the stud on which the tube end is fitted. The arrangement is such that when this screw or bolt is tightened the two shells are assembled with each other and the stud is wedged within the handlebar forming tube.
However, in operation it was found that this wedging action was unnecessary for it is sufficient to keep the horizontal tube in position between the two substantially vertical uprights. Besides, the assembling and fastening operations are relatively long and tedious and must be carried out by taking care not to tighten the screws or bolts excessively since an untimely distortion of the shells would occur. On the other hand, assembling means of this character are relatively expensive due to the number of component elements involved. Finally, considering the differences normally existing between the curvatures of the upper ends of the metal wire uprights, it is a frequent occurence that the shells cannot fit exactly on the upright ends.